2.9 KiB
| title | date | tags | ||
|---|---|---|---|---|
| Arduino, Big Builder, and Make | 2024-01-05 |
|
Last night, I got Big Builder building Arduino sketches.
Big Builder is my Continuous Integration / Continuious Development (ci/cd)
solution for forgejo/gitea.
It's nothing revolutionary,
it's just a container with a bunch of pre-installed software,
and the gitea act_runner with a configuration to not try and use docker.
This means my builds are pretty quick,
and my network use is very low,
since I already have the tools I need to build stuff,
and don't have to download mulitple OS images every time I do a build.
Automating embedded systems builds
Arduino, it turns out,
has been including command-line build tools for a long time now.
Since I'm using Debian's Arduino package,
I get the older, poorly-documented arduino-builder.
But the newer arduino-cli has better documentation,
that helped me understand how to use the older command.
Using arduino-builder lets me keep the source code structured
in a way that makes sense to amateur developers:
they can just load it up in the IDE and not worry about my automation.
But it also lets me automate builds on my forgejo server,
and use the command-line to build everything,
the way I've been doing since the 80s.
Here's what I wound up with, to build a Leonardo image:
mkdir -p build/cache
arduino-builder \
-build-path $(pwd)/build/ \
-build-cache $(pwd)/build/cache/ \
-fqbn arduino:avr:leonardo \
-hardware /usr/share/arduino/hardware/ \
-tools /usr/share/arduino/tools/ \
-compile MockBand.ino
This results in build/MockBand.ino.hex,
which can then be given to avrdude to flash my board.
Easy!
For the mockband project,
I also needed to specify a custom USB VID/PID and a CPP definition.
After reading a lot of forums posts and code,
I discovered I could easily do this with arduino-builder,
with the -prefs= flag.
This allows you to override settings in boards.txt,
which is apparently what Arduino uses to build a gcc flags list.
Here's a trimmed-down version of what I implemented:
mkdir -p build/cache
arduino-builder \
-build-path $(pwd)/build/ \
-build-cache $(pwd)/build/cache/ \
-fqbn arduino:avr:leonardo \
-hardware /usr/share/arduino/hardware/ \
-tools /usr/share/arduino/tools/ \
-prefs="build.extra_flags=-DUSB_VID=0x1bad -DUSB_PID=0x0004 -DCDC_DISABLED" \
-compile MockBand.ino
My final step was to write a Makefile to do all this.
Since the build step is just one (long) command,
and the -prefs could easily use per-target variables,
make was an obvious tool.
Adding a target to run avrdude was simple enough, too.
I no longer need the Arduino IDE at all, but the project still works with it!
The result was a Makefile which can compile, flash, and package all three variants of the build. It's 43 lines long, including blank lines.